如何在不使用NotifyIcon的情况下获得系统托盘功能。上下文菜单?

我知道我用来获取系统托盘中图标的NotifyIcon类有一个ContextMenu属性。我不想用它来获得右键单击弹出菜单,因为它总是显示右键单击的弹出菜单,而从不做其他任何事情。当我的主窗体显示模态对话框时,我想右键单击以激活主窗体,而不是显示弹出菜单。

private NotifyIcon trayIcon;
private ContextMenu iconMenu;

private void frmMain_Load(object sender, EventArgs e) {
    // [...]
    this.trayIcon.MouseClick += new MouseEventHandler(trayIcon_MouseClick);
    iconMenu = new ContextMenu();
    // [...]
}

private void trayIcon_MouseClick(object sender, MouseEventArgs ea) {
    this.iconMenu.Show(Program.instanceFrmMain, new Point(System.Windows.Forms.Cursor.Position.X - Program.instanceFrmMain.Left, System.Windows.Forms.Cursor.Position.Y - Program.instanceFrmMain.Top));
}